Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be multiple-access systems capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include code-division multiple access (CDMA) systems, time-division multiple access (TDMA) systems, frequency-division multiple access (FDMA) systems, 3GPP Long Term Evolution (LTE) systems, and orthogonal frequency-division multiple access (OFDMA) systems.
Service providers are typically allocated blocks of frequency spectrum for exclusive use in certain geographic regions. These blocks of frequencies are generally assigned by regulators regardless of the multiple access technology being used. In most cases, these blocks are not integer multiples of channel bandwidths, hence there may be unutilized parts of the spectrum. As the use of wireless devices has increased, the demand for and value of this spectrum has generally surged, as well. Nonetheless, in some cases, wireless communications systems may not utilize portions of the allocated spectrum because the portions are not big enough to fit a standard or normal waveform. The developers of the LTE standard, for example, recognized the problem and decided to support many different system bandwidths (e.g., 1.4, 3, 5, 10, 15 and 20 MHz). This may provide one partial solution to the problem.
Flexible bandwidth systems, also referred to herein as scalable bandwidth systems, may provide for better utilization of bandwidth resources. However, some flexible bandwidth systems may face timing issues, including signaling alignment, when they include multiple carriers that utilize different bandwidths.